WASHINGTON
— Americans' support for the war on terrorism is so firmly rooted that a solid majority would now back the assassination of foreign leaders to achieve victory.

A new Christian Science Monitor/TIPP poll shows sizeable segments of the public support other "taboos," too: One in 3 could accept government-sanctioned torture of suspects. One in 4 could envision a scenario in which they'd back use of nuclear weapons.

The findings indicate how far sentiment has shifted, especially from the 1970s, when the CIA was denounced for helping to plot assassinations of foreign leaders. More telling, they reveal a nation struggling to reconcile two prominent facets of the American character: a deep respect for human rights versus a historical imperative to be safe and free from fear, at almost any cost.

"The American soul is in turmoil," says Wade Clark Roof, chairman of the religious studies department at the University of California at Santa Barbara. Attacks like those on Sept. 11 are akin to "primitive warfare between tribes," tending to elicit "a forthright, aggressive response," he says. Yet, over time, that reaction tends to be tempered by a more-reasoned approach.

The depth of commitment to this war, though, does not mean the events of Sept. 11 created a warmonger nation. Even if the terrorist attack untethered an American impulse to strike back, the Monitor/TIPP survey still finds wide disdain for use of chemical or biological weapons, for instance. Gaps exist, too, over what constitutes an acceptable tactic, with the biggest divide between men and women.

Among those who would back the previously unthinkable, the portent of their answer is not lost. "I'd hate to use nuclear weapons," says Judith, a computer programmer and mother of three in Cordova, Tenn., who asked that her last name be withheld. But "if there weren't any children involved, and it was the only way to kill terrorists, then, yes." Likewise with assassinations: "If it's going to stop all the terrorism," she could accept it.

Not surprisingly, the survey found strong support for President Bush's performance in fighting terrorism, with 82 percent calling it "excellent" or "good."

But 87 percent also agreed on this point: If Afghanistan's Taliban government is toppled, but Osama bin Laden and his top aides aren't captured or killed, the US will have failed in its first objective of the war. That clear idea of what constitutes victory may eventually pose a problem for the Bush administration, which has recently begun asserting that its goal is the fall of the Taliban and not necessarily the elimination of Mr. bin Laden.

In presenting four extreme scenarios, the poll provides a gauge for measuring how serious Americans are about winning. The most acceptable: assassinations, with 60 percent saying they "could envision a scenario in which they would support" the tactic; 35 percent could not.

In 1981, by contrast, a Gallup poll found that 82 percent said they could never support political assassinations. That was after a decade of widespread criticism of the CIA for promoting that tactic in Central and South America - and President Ford's 1976 executive order banning US involvement in political assassinations.

Indeed, lack of historical perspective may be one reason younger people are more accepting of government-sanctioned assassinations: Support among 18- to 24-year-olds is 65 percent, compared with 56 percent among those 65 and over.

"I think you have to take these people out," says Keith Malinak, a 20-something Texan, about terrorism supporters like Iraq's Saddam Hussein. He knows there may be consequences. "If that means a wider war, that means a wider war," he says with a resigned air. But "this country has a history of doing what's necessary to win wars."

One difference between the 1980s and today is a more concrete threat. "We disapprove of assassinations in principle," but when a specific opponent - such as bin Laden - becomes sufficiently menacing, "we approve of it right away," says Sheldon Appleton, a political scientist at Oakland University in Rochester, Mich. It's the tension, he says, between maintaining high principles and wanting to protect ourselves.

Yet even today, not everyone is convinced: 53 percent of women and 68 percent of men back assassinations - a 15-point spread. Also, 54 percent of Democrats and 69 percent of Republicans could support them.

Next on the most-acceptable list is torture of suspects, which 32 percent support.

Finally, 27 percent could support using nuclear weapons, compared with just 10 percent for use of chemical or biological weapons - even though nuclear weapons are typically far more destructive. Observers attribute the gap to the menacing image of biological and chemical weapons - as used by Saddam Hussein in Iraq or in the recent anthrax attacks here. Nuclear weapons, by contrast, are a more distant memory, having been used in the 1940s in the US attacks on Japan that killed about 200,000 people.

Debates over all the tactics represent a national soul-searching over how to fight a just war.

The question for a nation defending itself and its Western ideals is: "How do you get a good result to come out of a bad thing - war?" says Michael Birkner, a historian at Gettysburg College in Pennsylvania. "We have to weigh it all, and ask, 'Do the ends justify the means?' "